This proposal "Psychosocial Factor Outcome Study in Sudden Cardiac Death (PFOS)" constitutes an independent project complimentary to the ongoing NIH clinical trial, "Sudden Cardiac Death Heart Failure Trial (SCD-HeFT)." The PFOS study will 1) assess psychosocial (Psychological: anxiety, depression; social: social support, pet ownership, life stress) status of 300 patients enrolled in the SCD-HeFT clinical trial at baseline, after one month, and every six months for 2 years; 2) investigate the independent contributions of baseline psychosocial factors to survival of heart patients (HF) patients; 3) evaluate the impact of implanted cardioverter defibrillators (ICD) on the psychosocial status of heart failure (HF) patients who receive ICD as primary prevention for sudden cardiac death (SCD); and 4) compare the psychosocial impact of ICD with the impact of the other HF treatments. The SCD-HeFT, primary prevention trial, is designed to compare the effectiveness of three randomly assigned treatments in improving survival for patients with HF. The three treatments are: conventional therapy of HF and placebo, conventional therapy of HF and Amiodarone, and conventional therapy of HF and ICD. PFOS will utilize SCD-HeFT physiological and demographic data. Specific hypotheses will be tested with a minimum power of .8, using logistic multiple regression, linear multiple regression, chi-square, and multivariate analysis of variance. Heart failure affects 1-2 million people in the United States. As mortality from myocardial infarction has decreased due to improved treatment, the number of people living with HF has increased. Over half of the deaths from HF are due to SCD. The results of the PFOS have potential to influence nursing practice, save lives of HF patients, and prevent escalated health care costs as HF progresses. Nursing plays a major therapeutic role in the management of cardiac patients and their families. It is imperative to target interventions to maximize effectiveness at decreasing mortality and morbidity. The PFOS will identify a high-risk profile for HF patients. Using this profile, nurses can identify patients at greatest risk and develop interventions to modify the forms of psychosocial distress, which specifically contribute to SCD and long term psychosocial distress. The combination of data from PFOS and SCD-HeFT will provide a holistic assessment of HF patients.